The long-term objectives of this research are to determine how molecular nitrogen can be reduced to ammonia under ambient conditions employing a well-defined transition metal complex, protons, and electrons, and/or to some organic molecule that contains nitrogen, at first stoichiometrically, and ultimately catalytically. The near-term objective is to prepare new di- or triamido/donor ligands and explore the chemistry of (primarily) Mo complexes that contain these ligands, especially chemistry that is relevant to the reduction of dinitrogen, including the chemistry of complexes that contain N2RX (X=0-4) or NRy (y=0-3) ligands. In general we wish to determine what principles are of fundamental and general significance to the activation and reduction of dinitrogen at one or two metal centers (homobimetallic or heterobimetallic). We will focus molybdenum as the activating metal for dinitrogen, although analogous chemistry of tungsten will be carried out in order to compare it to molybdenum. The most common metal to be employed in heterobimetallic chemistry will be iron.